简介
DSA是Schnorr和ElGamal签名算法的变种，被美国NIST作为DSfS(DigitalSignature Standard)。
DSA是基于整数有限域离散对数难题的，其安全性与RSA相比差不多。DSA的一个重要特点是两个素数公开，这样，当使用别人的p和q时，即使不知道私钥，你也能确认它们是否是随机产生的，还是作了手脚。RSA却做不到。
算法分类信息：
java实现：
package com.zoo.lion.security;import mons.codec.binary.Hex;import java.security.*;import java.security.interfaces.DSAPrivateKey;import java.security.interfaces.DSAPublicKey;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;/*** @Author: xf* @Date: /6/5 10:05* @Version 1.0*/public class DSA {private static String src = "dsa security";public static void main(String[] args) throws Exception {jdkDSA();}public static void jdkDSA() throws Exception {//1.初始化密钥KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("DSA");keyPairGenerator.initialize(512);KeyPair keyPair = keyPairGenerator.generateKeyPair();DSAPublicKey dsaPublicKey = (DSAPublicKey) keyPair.getPublic();DSAPrivateKey dsaPrivateKey = (DSAPrivateKey) keyPair.getPrivate();//2.执行签名PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(dsaPrivateKey.getEncoded());KeyFactory keyFactory = KeyFactory.getInstance("DSA");PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);Signature signature = Signature.getInstance("SHA1withDSA");signature.initSign(privateKey);signature.update(src.getBytes());byte[] res = signature.sign();System.out.println("签名：" + Hex.encodeHexString(res));//3.验证签名X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(dsaPublicKey.getEncoded());keyFactory = KeyFactory.getInstance("DSA");PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);signature = Signature.getInstance("SHA1withDSA");signature.initVerify(publicKey);signature.update(src.getBytes());boolean bool = signature.verify(res);System.out.println("验证：" + bool);}}
